Children's
Height Affected By Medications For ADHD
Study Shows Slower
Growth
Stimulant medications
used to calm children with attention deficit hyperactivity disorder
may have an unexpected side effect - slightly slower growth,
according to a study appearing in the medical journal Pediatrics.
Researchers report
that after two years of follow-up, stimulant medications used
to treat ADHD are still effective, but they may slow growth
in height a small amount.
"Stimulant medications
are really extremely safe medications with very few side effects,"
says study co-author Dr. James Swanson, a psychologist
and professor of pediatrics at the University of California,
Irvine.
"I don't think this
is necessarily a cause for great alarm in parents," Dr. Swanson
says. "The effect was rather modest, only about a centimeter
(about one-third inch) less over a year."
ADHD is the most common
of the psychiatric disorders that appear in childhood. Estimates
suggest that between 3 percent and 5 percent of all adolescents
have ADHD. Boys are two to three times more likely to have ADHD
than girls.
Growth
Slowed Early; May Come Later
Dr. Swanson also noted
that many questions remain unanswered. For example, researchers
do not know if children on ADHD medications will have a
growth rebound later.
He added that many
children with ADHD are larger than average for their age, so
the slight growth reduction for those on medication may just
put them back into the normal height range.
It is estimated
that 2 million children in the US have ADHD, according to the
National Institute of Mental Health. That translates
to almost one child with ADHD in every classroom. Symptoms include
an inability to focus, hyperactivity, and impulsivity.
For the current study,
Dr. Swanson and his colleagues followed up with 540 children
with ADHD who had participated in an earlier randomized clinical
trial. The trial compared the use of the stimulant medication
Ritalin to behavioral therapy, a combination of Ritalin and
behavioral therapy, or no treatment.
Children in the study
were recruited from six sites across the US and one in Canada.
All were between seven and nine years old at the start
of the study.
The first study lasted
14 months, and researchers found that the children who received
medication or medication in conjunction with behavioral therapy
had fewer symptoms than those who received no medication.
Children on medication
also grew slightly less than their non-medicated peers. Children
on medication alone gained 1.9 inches centimeters, while those
on combination therapy grew 1.7 inches.
Youth receiving behavioral
therapy grew an average of 2.4 inches, while a "control" group
of children grew 2.2 inches.
After 24 months, the
researchers followed up with the study participants and found
that symptom reduction difference in the medication and non-medication
groups had dropped by 50 percent.
Dr. Swanson says the
researchers suspected this change was due to children in the
medication group no longer taking their medication, or because
those in the non-medication group may have started taking medication.
That is because
the researchers only supervised treatment for the first 14 months.
After that, treatment decisions were made by the parents and
the children's physicians.
For the new study,
the researchers re-interviewed the children and parents to assess
what was truly happening in treatment. With the new information,
Dr. Swanson says they found that both the effects of medication
and the effects of behavioral therapy were actually fairly consistent
throughout the 24 months.
They also confirmed
that children on medication showed a slight reduction in height,
but Dr. Swanson says the effect was less pronounced at 24 months.
He said those assigned to medication grew about a one-third
inch less per year than those not on medication.
Monitoring
Needed During Treatment
Dr. Ernest Krug, medical
director of Beaumont Hospital's Center for Human Development
in Royal Oak, Mich., says, "The issue of growth suppression
is something we always monitor in kids on medication.
"This study reinforces
the importance of careful follow-up of children when they're
on medication," Dr. Krug says. "It's a good idea for them to
be seen every three to four months."
With any medication,
parents should be convinced that the drug is providing beneficial
effects for their children without causing unreasonable side
effects, Dr. Krug said.
Always consult your
child's physician for more information.
Online
Resources
(Our Organization
is not responsible for the content of Internet sites.)
Centers
for Disease Control and Prevention (CDC)
National
Institute of Child Health & Human Development
National
Institute of Mental Health
National
Institutes of Health (NIH)
US
Food and Drug Administration
